Abstract: A vertically oriented hydraulic power unit for an elevator drive includes an outer tank for drive fluid and an inner tank for fluid used to submerge and cool a motor, the fluids being exchangeable to maintain temperature in the inner tank at or below a specified maximum temperature. Oil returning from an elevator piston is fed into the inner tank to keep the inner tank sufficiently cool.

Abstract: A vertically oriented hydraulic power unit for an elevator drive includes an outer tank for drive fluid and an inner tank for fluid used to submerge and cool a motor, the fluids being exchangeable to maintain temperature in the inner tank at or below a specified maximum temperature. Oil returning from an elevator piston is fed into said inner tank to keep the inner tank sufficiently cool.

Abstract: A vertically oriented hydraulic power unit for an elevator drive includes an outer tank for drive fluid and an inner tank for fluid used to submerge and cool a motor, the fluids being exchangeable to maintain temperature in the inner tank at or below a specified maximum temperature. Oil returning from an elevator piston is fed into said inner tank to keep the inner tank sufficiently cool.

Abstract: A hydraulic elevator includes a car engaged with a first hydraulic ram, a counterweight engaged with a second hydraulic ram, and a pump to transfer hydraulic fluid between the hydraulic rams. The counterweight hydraulically balances the car without the requirement of a roped connection between the car and counterweight. A fluid flow system controls the transfer of hydraulic fluid between the hydraulic rams. As a result, there is no tank or reservoir for hydraulic fluid.

Abstract: A transition valve for a hydraulic elevator includes a block, a spool, an actuator, and an end cap. The actuator may be either a solenoid type actuator or an electric motor type actuator. The end cap includes an opening permitting engagement between the actuator and the spool. In a particular embodiment, the actuator is an electric motor engaged with the spool via a crank and arm. This arrangement translates the rotational motion of the motor into linear motion of the spool with a sine curve profile.

Abstract: A control system for controlling the motion of a hydraulic elevator calculates a deceleration distance based upon the elevator velocity and begins the deceleration phase of the elevator motion upon the elevator reaching the calculated distance from the landing. In a particular embodiment, the control system includes a hydraulic valve, a space encoder, and a controller. The space encoder produces velocity and position measurements. The controller uses the velocity inputs to determine the deceleration distance and, upon the elevator car 14 reaching the calculated distance from the landing as measured by the position inputs from the space encoder, commands the hydraulic valve to actuate and begin the deceleration phase. In an alternate embodiment, an interface unit connected between the controller and the hydraulic valve calculates a delay between the deceleration command based upon a predetermined distance and the calculated deceleration distance based upon car velocity.